I suggested the shader background environment switcher, similar to mental rays.
It's handy to have a material library setup with combinations of hdri environment maps, back ground maps, (reflection and refraction if need be).
Scenes that require multiply lighting configurations are easy to setup this way, one shader for dusk, one for day light, etc..
Simple drag and drop a prepared environment shader into the background, its easy to transfer shaders around to other people in the office without needing the a 3dsmax scene.
I'd like direct lighting over ride for Glass materials, that have attenuation, instead of physically based caustics.
Tone mapping needs a "Do Not" effect background map.
Scene material override, have an option for material Buffer ID overrides, Instead of object based, this works better for multi-sub material objects.